Various water treatment methods for decreasing hardness of water are known and commercially employed. Detergents and other cleaning agents often contain numerous components to improve the cleaning activity of the detergent, including for example, components to counteract the effects of water hardness. Hard water is known to reduce cleaning efficacy both by forming films on surfaces and reacting with detergent and other cleaning components, making them less functional in the cleaning process. Various methods for counteracting and/or eliminating water hardness have been implemented by those skilled in the art, including for example, adding chelating agents or sequestrants into detersive compositions in amounts sufficient to handle the hardness ions and/or softening a water source via ion exchange. Ion exchange can be used to exchange hardness ions, such as calcium and magnesium, in the water with sodium or other ions associated with a resin bed in a water softening unit.
Various ion exchange methods are known by those skilled in the art. Most commonly, water is run through an exchange resin to adhere the hardness ions calcium and magnesium to a resin in the softener. However, when the resin becomes saturated it is necessary to regenerate the resin using large amounts of sodium chloride dissolved in water. This regeneration process has numerous known disadvantages, namely requiring the use of briny solutions and chloride from added sodium chloride used to flush out the resin. Accordingly, when water softeners regenerate they produce a waste stream that contains significant amounts of sodium, creating a burden on the system, e.g., sewer system, in which they are disposed of. The generated waste presents a multitude of downstream water re-use concerns, including for example water re-use applications like potable water usage and agriculture. Further, traditional water softeners add to the salt content in discharge surface waters, which has become an environmental issue in certain locations. These and other limitations of commercially-available water softening methods are described in further detail in U.S. patent application Ser. No. 12/764,621, entitled “Methods and Apparatus for Controlling Water Hardness,” the entire contents of which are hereby expressly incorporated herein by reference.
It is preferred that some means of water conditioning be employed for water sources to be used in formulating and/or diluting cleaning compositions. For example, useful water conditioning technologies include filtration and/or softening systems, such as via reverse osmosis (RO). A typical RO system includes a semipermeable membrane designed to permit passage of water (the solvent) and prevent passage of certain contaminants (the solutes). Pressure is applied to the incoming side of the membrane. The pressure may be supplied by the incoming water pressure and/or may be further adjusted using a pressure pump or other mechanism for increasing the incoming pressure. The contaminants are retained on the incoming side of the membrane and the purified water is allowed to pass through to the output side of the membrane. The contaminants may be flushed down a drain or otherwise disposed of, or in some applications can be reused. A typical RO generator may include one or more pre-filters, the RO membrane, and one or more post filters. The pre-filters remove particles such as sand, dirt, rust, and other sediment. The pre-filters may also include filters to remove chlorine, which may damage certain types of RO membranes. The RO membrane itself may include, for example, a TFC/TFM (thin film composite/material), a spiral wound CTA (cellulose tri-acetate). One or more post-filter(s) may be included to capture other chemicals not removed by the RO membrane.
However, there are various limitations to the use of such water conditioning methods, including RO systems. In particular, the large amount of waste water generated from the reverse osmosis process presents a significant limitation. In many instances, a conventional RO system rejects over 50% of the incoming water in need of treatment (e.g. efficiency is very low). Moreover, when the RO system is exhausted, the water is no longer softened (resulting in poor washing results on treated surfaces) and the parts are disposed.
In addition, it is often not desirable for a facility to condition its entire water supply to a building; therefore methods of conditioning as minimal a portion of a water supply as possible are desirable. Therefore, water treatment or conditioning is preferred for water sources employed as waters for dilution of cleaning compositions. Without water conditioning, most often, cleaning compositions are formulated to account for the lowest quality of water expected. As a result, cleaning compositions are formulated to include significant amounts of chemical water conditioning agents, such as chelating agents and/or water conditioning polymers, such as disclosed for example in the Background of U.S. patent application Ser. Nos. 12/764,621 and 12/764,606, which are herein incorporated by reference in their entirety. Similarly, cleaning compositions often exclude components dependent on softened water sources, due to the unreliability in source water conditions. For example, natural soaps are highly favorable from a sustainability standpoint in cleaning compositions (e.g. salts of natural fatty acids), however due to their minimal tolerance for hard water they are not often incorporated into cleaning compositions.
Accordingly, it is an object of the invention to provide a high quality, softened water source for use in dilution of cleaning compositions, to beneficially provide improved performance from conventionally generated cleaning compositions (e.g. employing an untreated water source from a facility).
In an aspect, the high quality, softened water source is provided according to specific water specifications desired for specific applications of use.
In an additional aspect, generated cleaning compositions according to the invention employ an additional set of ingredients (suitable for softened water compositions) can be formulated into compositions while reducing costs and reducing unnecessary chemical usage.
Accordingly, it is an objective of the claimed invention to develop improved methods and retrofitted systems for regenerating ion exchange resins for use in various institutional and industrial applications.
A further object of the invention is to develop a system and methods for using acid regenerate-able ion exchange resins to pre-treat water for the various institutional and industrial applications, resulting in the reduced demand for polymers and threshold reagents in cleaning compositions (e.g. detergents).
A further object of the invention is to improve cost effectiveness and quality of dispensed cleaning compositions using softened acidic water generated by the acid regenerate-able ion exchange resins at a point of use for dilution of a concentrate or generation of a cleaning composition.
Still further, the invention sets forth methods and systems for reducing scale build-up, spotting and/or film formation in cleaning compositions by treating a water source to be incorporated into a cleaning composition using an acid regenerate-able ion exchange resin.
A still further aspect of the invention is to apply acid cation exchange resins to improve water quality and thereby reduce the spotting and filming on treated glass surfaces, along with reducing the usage polymer and other threshold reagents in detergent.